When the position of a vehicle body is altered due to rapid acceleration, sudden slowdown or driving on an inclined slope in a state of a low fuel level, it changes the level of fuel in the fuel tank, making it difficult for a fuel pump to suck in the fuel. To enable the fuel pump to continue to suck in fuel in such driving conditions, there has been known a structure in which a cup is protruded to a lower part of a fuel tank, a suction part of a fuel pump is set in the cup, and an opening width of the cup is narrowed to make it easy for fuel to remain in a downward swelling part even if attitude of a vehicle is changed. One example of such a structure is disclosed in Japanese Patent Laid-Open No. 2000-72074.
However, even by use of the foregoing structure, when the vehicle climbs a steep slope for a relatively long distance, a necessary fuel may not be retained in the cup. Such a case may arise, for example, when the vehicle climbs up a steep slope (for example, a slope with a tilt angle of nearly 70°) such as in off-road racing and in trial racing. In such a situation, it may be required to continue suction of the fuel. Accordingly, it is an object of the invention of the present application to continue supply of the fuel for a predetermined time when the position of the vehicle body undergoes an extreme change.